x的三次方+2x的二次方减5x+6
问题描述：
x的三次方+2x的二次方减5x+6
答
x的三次方+2x的二次方减5x+6
=x^3+2x^2-5x-6
=x^3+x^2+x^2-5x-6
=x^2(x+1)+(x-6)(x+1)
=(x+1)(x^2+x-6)
=(x+1)(x+3)(x-2)